Coordinate measuring and testing machine

ABSTRACT

Multi-coordinate measuring and testing machine which is essentially constituted from a fundamental machine unit, a scanning or sensing system which is movable in at least two coordinate directions, and a machine-controlling unit. The scanning or sensing system is constructed as a multi-sensor system and is constituted from a mechanical sensing head or probe with at least one stylus and/or a video scanner and/or a laser scanner which are controlled from a microprocessor and operate independently of each other, and which are selectively either individually actuatable by means of software connected thereto, or can be coupled to each other in a dual or triple combination.

BACKGROUND OF THE INVENTION

The present invention relates to a multi-coordinate measuring andtesting machine which is essentially constituted from a fundamentalmachine unit, a scanning or sensing system which is movable in at leasttwo coordinate directions, and a machine-controlling unit.

Multi-coordinate measuring and testing machines of that type are countedas being within the general state of technology, and in practicalapplications, have been introduced a multiplicity of constructions.

2. Discussion of the Prior Art

Current measuring machines, as a rule, are constructed in portal or agantry-type constructional mode, and are equipped with a mechanicalprobe or sensor head possessing measuring sensors. Other known measuringand testing machines concern themselves with non-contacting measurement;for example, through the intermediary of interferometer systems.Considered by themselves, both methods of measurement are subject to aseries of advantages and also disadvantages.

Thus, for example, known from the disclosure of German Laid-open PatentApplication 36 16 812 is a coordinate measuring device with anarrangement for the non-contacting scanning or sensing of the measuredobject. Through the intermediary of an interferometric linearmeasurement system, the path of displacement of a measuring mirror foreach measuring coordinate, which is fixedly interconnected with thecoordinate table. Hereby, the reference mirror of the interferometriclinear measurement system is rigidly connected with the scanning systemfor the measured object such that, with relatively minor technologicalexpenditures, there can also be determined even extremely minutedisplacements of the imaging objective in comparison with the measuredcoordinate direction and enabling the preclusion of any influencescaused by tilting errors.

The specification of German OS No. 36 16 345 discloses an interferometersystem for linear and angular measurement, which is constituted from atotal of two interferometer systems, so as to be able to simultaneouslyimplement, at a high degree of precision, linear and angularmeasurements as well as measurements of refractive index.

The principle of the interferometric linear measurement is already knownsince the year 1890 from the Michelson Interferometer. However, it isalso known that a laser interferometer which is utilized as a linearmeasurement system, necessitates a not inconsiderable additionalexpenditures in contrast with other; for instance, mechanical sensor orscanning heads. Through the use of laser interferometer systems therecan be achieved a resolution or definition of up to 0.01 μm. However,the length of the laser lightwave is dependent upon the temperature, thepressure and the humidity in the region which is traversed by themeasuring beam. Any fluctuation in these environmental conditions willact without inertia or delay on the results of measurement. Thissignifies that, on the one hand, laser interferometer-linear measurementsystems afford an extremely good capability for a precise non-contactingmeasurement; however, on the other hand, under unfavorable environmentalconditions, are capable of delivering erroneous measurement results.

In addition to the above-mentioned non-contacting measuring systems,mechanical sensing or scanning systems are considered to be within theknown general state of the technology. These mechanical sensing systemsfor multi-coordinate measuring machines consist essentially of a spindleon which there is mounted a probe or sensor head, having styli; providedthereon, and sensor balls or spheroids on tips of the styli. Themechanical sensing systems are relatively robust and possess an adequatedegree of precision in their measurement. The deflection of the styluscan be either translatory or rotational and, upon contacting theworkpiece, generates control signals for the drives. These signalsfacilitate the provision of constant-remaining, reproduceable orrepeatable contacting conditions. In the known sensing systems, afurther distinction is made between the measuring and switching systems.

In the measuring sensing systems, in the position of measurement thedeflection of the probe stylus is determined through systems formeasuring small displacements; whereas in the switching sensor systems,upon reaching of the defined contacting position or a define sensordeflection, a switching signal is generated in the stylus.

Heretofore, prior to the purchase and installation of a coordinatemeasuring and testing installation, an expert in this technology alwaysneeded to extremely carefully investigate the conditions in theutilization and measuring tasks prior to deciding on one or the otherinstallation; namely, either the non-contacting or mechanical sensingsystem. The provision of both variants of the installations wasfrequently prohibitive due to space limitations, and integrating as wellas cost reasons.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to develop amulti-coordinate measuring and testing installation which, independentlyof environmental conditions, is employable for measuring and testing orinspecting tasks which are encounted in actual practice, and which issimply implementable and at a relatively low technological expenditure.

Inventively, the foregoing object is attained pursuant to the invention,in that the scanning or sensing system is constructed as a multi-sensorsystem and is constituted from a mechanical sensing head or probe withat least one stylus and/or a video scanner and/or a laser scanner whichare controlled from a microprocessor and operate independently of eachother, and which are selectively either individually actuatable by meansof software connected thereto, or can be coupled to each other in a dualor triple combination. Hereby, in a preferred embodiment of theinvention, for the control or actuation of the entire multi-sensorscanning or sensing system, there need be installed only a singlesoftware and the laser scanner and video scanner may be located alongthe same beam path.

Through this arrangement, within a single unit the measuring and testinginstallation avails itself of all known advantages of the individualscanning or sensing systems. By means of this multi-coordinate measuringand testing center, in an optimum manner it is possible to solve allencountered measuring tasks and under all environmental conditions. Themeasuring and testing center can be assembled as a single unit. Just aswell, it can also be integrated into transfer machine installations orprocessing or work treatment centers, and as a result thereofintroduceable into the work flow or production line. The coordinatemeasuring and testing installation, pursuant to the features of theinvention, unites the non-contactingly operating video scanner, thelaser-scan system and the contacting measuring probe. Thus, there can benon-contactingly automatically measured suitable surface contours, aswell as expedited pure measuring tasks, whereby the entire installationoptimally fulfills these tasks without the need for any refitting. Theinserted software coordinates the communication with the video-processorsystem and the CNC movement control over the installation. In accordancewith the inventive concept, the inserted different scanning systems cancarry out independently of each other and alternatively the requiredmeasuring and testing tasks. Just as well, they can also be coupled toeach other in a dual or triple combination, and fulfill measuring andtesting tasks in parallel with each other, and finally can be socontrolled or actuated that the required measuring and testing tasks canbe implemented by means of the scanning systems in succession and ininterchangeably different dual and triple combinations.

Pursuant to a particular feature of the invention, there can be providedtwo spindles which are movable in the Z-coordinate direction, of whichone spindle supports the mechanical probe with styli, and the otherspindle the video scanner and laser scanner. In this case, the spindlescan be arranged on a common measuring carriage.

In accordance with a further feature of the invention, there can beprovided a separate measuring carriage can be movable in synchronism aswell as also separately of each other in, selectively, the same ordifferent coordinate directions.

The least technological expenditure is encountered when the spindleswhich are inserted in the Z-direction, together with the respectivescanning systems, are mounted on a common carriage or other kind ofsupport. Thereby, it is ensured that for certain measuring and testingtasks there is obtained, for instance, a reduction with respect to themeasuring period. Through the receipt of the two spindles on separatemeasuring supports, there are achieved a series of advantages. Themeasuring carriages, within the contexts of the invention, can bemovable in synchronism in either the same or different coordinatedirections. They can just as well be displaced at different times in thesame or different coordinate directions. The large number ofpossibilities which are connected with this type of the spindle mountingaffords a measurement and testing under varying conditions and thesolution of even complicated measuring tasks within a short period oftime. Through the combination of the scanning systems in a singlemachine installation, there can be further tested the measured resultsof the one system by means of the other system.

Pursuant to a further aspect of the invention, the laser scanner can beutilized in a scanning operation as well as autofocus.

According to a further feature of the invention, the laser scanner,during scanning operation, continually regulates the movement of theZ-axis in correlation with the surface contour whereby, advantageously,the scanning direction is expediently predeterminable in the X andY-axis. In order to be able to continually regulate thecontour-detecting measuring axis in real-time within the effective laserrange, and to afford high scanning speeds at a concurrently high degreeof precision in measurement of about 0.5 μm, and an adjustablemeasurement definition of 0.1 μm to 10 μm, the laser scanner can duringscanning operation can follow non-contactingly at a constant distancethe surface contour of a workpiece in the X and Y-coordinate directions,whereby the laser scanning system is formed from two interlinked closedcontrol circuits, of which the first control circuit correlates thetransmitting power of the laser with the reflective characteristic ofthe workpiece, and in dependence upon the receiving signal in thereceiver controls the transmitting signal in the transmitter, whereasthe second superposed control circuit controls the continual follow-upof the carriage or; in essence, the spindle in the Z-direction into theoptimum housing plane.

Hereby, in an advantageous embodiment, the receiver system can beequipped with differentiating diodes, through which there is generated adifferential signal in conformance with the focused position of theobjective, which by means of an axial amplifier and a servomotorautomatically positions the Z-axis in the focusing plane. The measuringcarriages, or in essence, the spindle with the laser scanner, can possesa measuring system with a glass measuring rod of the Z-axis and toconvey the current position of height along the Z-axis to the maincomputer.

Pursuant to a still further embodiment, the video scanner can pick upmeasuring points along the outer contour of the workpiece, which aredetermined from a digitalized picture produced by a video processor forthe applicable workpiece segment. The contours of the workpiece in theX- and Y-coordinates can hereby be determinable through edge tracingroutines in the digitalized picture, and the measuring points in theZ-direction can be formed with a focusing apparatus and the camerapicture or through a high-precision laser-focusing system. During theedge tracing routine individual measuring points are interlinked witheach other into a measuring program. The digitalized picture can be agray picture as well as a binary picture.

Finally, the mechanical probe can, selectively, be a switching or ameasuring probe, and the fundamental machine unit can be constructed ina portal or gantry-like structure with a solid base, which for thereceipt of the workpieces selectively includes a turntable, and on atraverse receives the measuring carriage or carriages for the spindleslongitudinally displaceably in a direction of travel which is at rightangles to or extends in the same direction as the gantry, whereby in themeasuring carriage or carriages and the spindles are controllable from acontrol panel, and the obtained results of measurement on the picturescreen of a display unit and/or by means of a printer.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference may now be had to the following detailed description ofexemplary embodiments of the invention, taken in conjunction with theaccompanying drawings; which:

FIG. 1 illustrates in a simplified perspective representation athree-coordinate measuring installation pursuant to the presentinvention;

FIG. 2 illustrates a simplified perspective representation of athree-coordinate measuring installation with two measuring carriages forthe Z-spindles; and

FIG. 3 illustrates a block circuit diagram of a the laser scanningsystem with an autofocusing system.

DETAILED DESCRIPTION

The three-coordinate measuring installation 1 pursuant to FIGS. 1 and 2is a measuring machine, or fundamental machine unit, which isconstructed in the mode of a portal or gantry-like structure with astationary portal 2 which is formed from the two side pillars orsupports 3 and the traverse 4. The traverse 4 concurrently representsthe guide track 5 for the cross-carrier 6, the latter of which supportsitself through a support 7 on the second guide track 8. Thecross-carrier 6 is displaceable above a measuring table 9 along the twoguide tracks 5 and 8 which are arranged in parallel with each other,until it contacts end stops, which table is installed between the portal2 and the guide track 8. The measuring table 9, pursuant to FIG. 2, isconstructed as a measuring turntable 10.

Reference numeral 11 represents an input or programming panel.Iadd., ormachine control unit, .Iaddend.or a function panel, through theintermediary of which there can be called up the individual functions ofthe measuring installation 1. In order to convert the commands intocorresponding functions, a computer.Iadd., or microprocessor,.Iaddend.12 is arranged between the input panel 11 and the measuringinstallation 1. The results of measurement are displayable or recordableon a picture screen 13 and/or a printer 14. For this purpose, thepicture screen 13 of a display unit and similarly the printer 14 areconnected with the central computer 12 through the electrical lines 15.The line 16 from the computer 12 is connected with drive elements; forinstance, drive motors for the movement of travel of the cross-carrier 6and carriages 17 and 18, and with electronic devices of the scanningsystem.

The schematic and simplified representation of the three coordinatemeasuring machine or installation is only one of possible types ofconstruction. Instead of the illustrated embodiment, there can naturallybe expediently employed other known types of constructions, withoutdeviating from the scope of the invention and the field of application.

A carriage 17 is arranged on a cross carrier 6, and which is movablethereon offset by 90° relative to the direction of travel of thecross-carrier 6. The measuring carriage 17 receives two spindles 20 and21 which are displaceable in the Z-direction 19.

In accordance with FIG. 2, two measuring carriages 18 are arranged onthe cross-carrier 6 so as to be displaceable along the cross-carrier 6.Both measuring carriages 18 each possess, respectively, a spindle 20 and21 which are movable in the Z-direction 19, and which are actuatableindependently of each other. The measuring carriages 18 can bedisplaceable in synchronism in either the same or opposite directions.They can be alternatively movable and carry out different directions oftravel and types of movement.

The spindles or sleeves 20 and 21 are similarly so actuated so as to bemovable in synchronism in the same as well as opposite directions, orcarry out alternative movements.

In the illustrated exemplary embodiment, the spindle 20 presently mountsthe switching sensor head or probe 22, and the spindle 21 mounts thevideo scanner 23 and the laser scanner 24. Naturally, the reversearrangement is also possible with this construction.

For the determination of the contour of the workpiece surfaces 25, thethree-coordinate measuring installation 1 is equipped with a laserscanner 24, on the spindle 21, through which there are automaticallymeasured non-contactingly suitable surface contours. In contrast withlasers which operate pursuant to the triangulation method, the laserscanner employed therein follows the surface contour at a constantdistance therefrom. This method possesses the advantage that thecontour-determining measuring axis is continually regulated in real-timewithin the effective laser range and read-off by the central computer12. Resulting therefrom is a high scanning speed and a high degree ofprecision in measurement. The essential technological advantages of theinserted laser scanner 24, which is hereinbelow described in moreprecise detail, are as follows:

1. Non-contacting determination of measurements which are free ofmeasuring forces.

2. High scanning speed.

3. Adjustable measuring definition of 0.1 μm to 10 μm.

4. High degree of measuring precision of 0.5 μm.

The laser scanner 24 continually regulates the movement along the Z-axis19 in conformance with the surface contour. The scanning direction alongthe X-axis and Y-axis by means of the measuring carriages 17 and 18 andthe cross-carrier 6 are expediently predeterminable through the inputpanel 11 with computer 12. Underlying the scanning principle predicatedis the so-called light-intersection method, in which the reflectingsurface of the workpiece 26 is utilized as a reference for focusing.Serving as a light source 27 is an impulse laser diode 28, whoseluminescent surface is imaged by means of an optical system through theoptical axis 29 of the presently employed lens system 30 onto theworkpiece surface 25. The light beam 31 emanating from the impulse-laserdiode 28 strikes against a mirror 32 which is angled at 45°, isdeflected from there towards a lens 34 and concurrently again conductedagain to a second mirror 33 angled at 45°, and from the latter to thelens 30 over the workpiece surface 25. From there, the light beam 31 isreflected, and by means of the mirrors 33 and 32 retransmitted to thelens 34. Thus, the workpiece 26 remits a portion of the reflected laserlight through the lens 30 and optical system 33, 32, 34 onto a receiversystem 36 which is equipped with the differentiating diodes 35. On thebasis of this type of imaging which is applied in this system, themeasuring point wanders out during the defocusing and generates adifferential signal in the linear amplifier 37, which positions theZ-axis 19 again in the focusing plane through the intermediary of aservomotor 38. At 39 the measuring point is displaced towards plus bythe value of ΔF, whereas at 40 there is effected the displacementtowards minus by the value of ΔF. In conformance with the opticalsystem, these measuring points are reflected to the differentiatingdiodes 35, and transmitted further in the receiver 36 as a signalthrough the transmitter 28 for correlating of the measuring carriage 18in the Z-coordinate 19.

As is further ascertainable from FIG. 3, in addition to laser scanner24, the spindle 21 also possesses the video scanner 23 which isessentially constituted from a camera 41 with a picture-processingdevice 42. The video scanner 23 operates in a non-contacting mode alongthe Z-axis 19 through the lens 30 on the workpiece surface 25. Thedetermination of the individual measuring points on a workpiece 26 whichis to be considered is effected on the basis of a gray image of thesegment o the measured object which is digitalized by a video processor43. The measuring points are hereby picked up at the outer contour ofthe workpiece 26. The applicable contours in the X and Y-directions aredetermined by edge finding or tracing routines in the gray image;whereas in the Z-direction 19, the measuring points are formed with theautomatic focusing apparatus and with the assistance of the camerapicture, or with a high-precision laser-focusing system.

FIG. 3 illustrates in principle, two interdigitating control circuits 46and 47. The control circuit 46 through the interconnection 48 controlsthe control signal in the transmitting system 28 in dependence upon thereceiving signal. The control circuit 46 determines the transmittingpower of the continuous-wave laser 24 with respect to the currentreflective characteristics of the workpiece 26.

The control circuit 47 is superimposed on the control circuit 46 andcontrols the autofocus through the servomotor 38. Hereby, there isfacilitated the continual follow-up of the entire carriage 21 in theZ-direction is facilitated for a constantly optimum focusing plane. Theposition of the carriage 21 in the Z-direction is maintained through ameasuring system 49 with a glass measuring rod, and transmitted to themain computer 12 through an electrical line 50.

The servomotor 38 is drivingly interconnected with the spindle 21 forthe movement in the z-coordinate direction, as is indicated by referencenumeral 51.

In order to be able to emphasize edges under conditions of poorcontrast, there can be employed filters for the gray image. For thedescription of the nominal geometry of the workpieces there areavailable the known basic geometric elements, such as point, line,circle, ellipse, plane, cylinder, sphere and cone.

The switching sensor head or probe 22 has a suitable undefined sensingdeflection and a switch point for the microswitch in the probe. Thescanning is carried out mechanically with the stylus 44 along thesurface of the workpiece. Through the scanning contact, there isactuated microswitch in the probe 22 and an impulse is transmitted tothe computer 12, which represent a measured result. The stylus 44, in ausual manner supports a sensing ball 45 at its free end.

It is of considerable importance that the laser scanner 24 and the videoscanner 23 are located or operate along the Z-axis 19 within the samecommon beam path 52. Only then is it possible that by means of bothsystems; in effect, from the video scanner 23 with the video camera 41and a picture processing installation 42, and from the laser scanner 24with the impulse-laser diode 28 and the lens 34, as well as the mirrors32, 33, there is always determined the same measuring point on theworkpiece 26.

What is claimed is:
 1. Multi-coordinate measuring and testinginstallation, comprising a fundamental machine unit; a scanning system.Iadd.mounted upon said fundamental machine unit and .Iaddend.movable inat least two coordinate directions; and a machine control unit .Iadd.forinputting commands for controlling operation of said scanningsystem.Iaddend., said scanning system being a multi-sensor scanningsystem constituted of a mechanical probe having at least one sensingstylus, a video scanner and a laser scanner; a microprocessor.Iadd.interconnected with said machine control unit .Iaddend.forcontrolling said sensing stylus and .[.scanner.]. .Iadd.scanners.Iaddend.so as to be operable independently of each other and beingselectively actuatable .[.along.]. .Iadd.alone .Iaddend.through softwareor coupleable to each other in a dual or triple operative combination,said video scanner and the laser scanner being arranged on a common beampath for detecting the same measuring point on a workpiece.
 2. Aninstallation as claimed in claim 1, wherein a single said software isprovided for the actuation of the entire multi-sensor scanning system.3. An installation as claimed in claim 1, comprising two spindlesmovable in a Z-coordinate direction, one said spindle mounting themechanical probe having sensing styl; and said other spindle mountingsaid video scanner and said laser scanner.
 4. An installation as claimedin claim 3, wherein said spindles are arranged on a common measuringcarriage.
 5. .[.Am.]. .Iadd.An .Iaddend.installation as claimed in claim3, wherein a measuring carriage is provided for each said spindle, saidspindles being movable in synchronism and also separately of each otherin selectively the same or different coordinate directions.
 6. Aninstallation as claimed in claim 4 or 5, wherein said laser scanner isemployable in a scanning operation and also in autofocus.
 7. Aninstallation as claimed in claim 6, wherein said laser scanner duringscanning operation non-contactingly follows the surface contour of aworkpiece being measured at a constant distance therefrom along the Xand Y-coordinate directions, said laser scanning system comprising.[.two.]. .Iadd.first and second .Iaddend.interlinked closed controlcircuits, .[.a.]. .Iadd.said .Iaddend.first .[.said.]. control circuitdetermining the transmitting power of the laser relative to thereflective characteristics of the workpiece and in dependence upon areceiving signal in a receiver controlling a transmission signal in atransmitter, and .[.the.]..Iadd.said .Iaddend.second .[.saidsuperimposed.]. control circuit controlling the continual follow-up ofthe measuring carriage and spindle in the Z-direction into an optimumfocusing plane.
 8. An installation as claimed in claim 7, wherein saidreceiver includes differentiating diodes for generating a differentialsignal in conformance with the focusing setting of a lens, said Z-axisbeing automatically positioned through a linear amplifier and servomotorinto the focusing plane.
 9. An installation as claimed in claim 7,wherein said measuring carriage and spindle for the Z-axis includes ameasuring system with a glass measuring rod, and the present position ofelevation is conveyed to a main computer.
 10. An installation as claimedin claim 1, wherein the video scanner receives measuring points alongthe external contour of the workpiece said measuring points beingdetermined by a digitalized picture of a respective segment of theworkpiece which is generated by a video processor, the contours of saidworkpiece being determinable along the X and Y-coordinates through edgetracing routines in the digitalized picture, and the measuring points inthe Z-direction being formed with a focusing means and the camerapicture or a high-precision laser focusing system.
 11. An installationas claimed in claim 1, wherein said mechanical probe is selectively aswitching or a measuring probe.
 12. An installation as claimed in claim4 or 5, wherein the fundamental machine unit comprises a portal-likegantry structure having a solid base, selectively including a measuringturntable for receiving the workpiece, and a cross-carrier supportingthe measuring carriage for the spindles for longitudinal displacementthereon in a direction of travel at right angles or equally directedrelative to said gantry structure, said measuring carriage or carriagesand the spindle or spindles being controllable from a control panel andthe obtained results of measurement being recordable on a picture screenof a display unit or selectively on a printer. .Iadd. 13.Multi-coordinate measuring and testing installation, comprising afundamental machine unit; a scanning system mounted upon saidfundamental machine unit and movable in at least two coordinatedirections; and a machine control unit for inputting commands forcontrolling operation of said scanning system, said scanning systembeing a multi-sensor scanning system consisting of a mechanical probehaving at least one sensing stylus, and a non-contacting scannerselected from the class comprising a video scanner and a laser scanner;a microprocessor interconnected with said machine control unit forcontrolling said sensing stylus and said non-contacting scanner so as tobe operable independently of each other and being selectively actuatablealone through software or coupleable to each other in a dual operativecombination. .Iaddend. .Iadd.
 14. An installation as claimed in claim13, wherein a single said software is provided for the actuation of theentire multi-sensor scanning system. .Iaddend. .Iadd.15. An installationas claimed in claim 13, comprising two spindles movable in aZ-coordinate direction, one said spindle mounting said mechanical probehaving said sensing stylus; and said other spindle mounting saidnon-contacting scanner. .Iaddend. .Iadd.16. An installation as claimedin claim 15, wherein said spindles are arranged on a common measuringcarriage. .Iaddend. .Iadd.17. An installation as claimed in claim 15,wherein a measuring carriage is provided for each said spindle, saidspindles being movable in synchronism and also separately of each otherin selectively the same or different coordinate directions. .Iaddend..Iadd.18. An installation as claimed in claim 16 or 17, wherein saidnon-contacting scanner is a laser scanner, said laser scanner beingemployable in a scanning operation and also in autofocus. .Iaddend..Iadd.19. An installation as claimed in claim 18, wherein said laserscanner during scanning operation non-contactingly follows the surfacecontour of a workpiece being measured at a constant distance therefromalong the X and Y-coordinate directions, said laser scanning systemcomprising first and second interlinked closed control circuits, saidfirst control circuit determining the transmitting power of the laserrelative to the reflective characteristics of the workpiece and independence upon a receiving signal in a receiver controlling atransmission signal in a transmitter, and said second control circuitcontrolling the continual follow-up of the measuring carriage andspindle in the Z-direction into an optimum focusing plane. .Iaddend..Iadd.20. An installation as claimed in claim 19, wherein said receiverincludes differentiating diodes for generating a differential signal inconformance with the focusing setting of a lens, said Z-axis beingautomatically positioned through a liner amplifier and servomotor intothe focusing plane. .Iaddend. .Iadd.21. An installation as claimed inclaim 20, wherein said measuring carriage and spindle for the Z-axisincludes a measuring system with a glass measuring rod, and the presentposition of elevation is conveyed to a main computer. .Iaddend..Iadd.22. An installation as claimed in claim 13, wherein saidnon-contacting scanner is a video scanner, said video scanner receivingmeasuring points along the external contour of the workpiece saidmeasuring points being determined by a digitalized picture of arespective segment of the workpiece which is generated by a videoprocessor, the contours of said workpiece being determinable along the Xand Y-coordinates through edge tracing routines in the digitalizedpicture, and the measuring points in the Z-direction being formed with afocusing means and the camera picture or a high-precision laser focusingsystem. .Iaddend. .Iadd.23. An installation as claimed in claim 13,wherein said mechanical probe is selectively a switching or a measuringprobe. .Iaddend. .Iadd.24. An installation as claimed in claim 16 or 17,wherein the fundamental machine unit comprises a portal-like gantrystructure having a solid base, selectively including a measuringturntable for receiving the workpiece, and a crosscarrier supporting themeasuring carriage for the spindles for longitudinal displacementthereon in a direction of travel at right angles or equally directedrelative to said gantry structure, said measuring carriage or carriagesand the spindle or spindles being controllable from a control panel andthe obtained results of measurement being recordable on a picture screenof a display unit or selectively on a printer. .Iaddend. .Iadd.25.Multi-coordinate measuring and testing installation, comprising afundamental machine unit; a scanning system mounted upon saidfundamental machine unit and movable in at least two coordinatedirections; and a machine control unit for inputting commands forcontrolling operation of said scanning system, said scanning systembeing a multi-sensor scanning system consisting of a video scanner and alaser scanner; a microprocessor interconnected with said machine controlunit for controlling said video scanner and said laser scanner so as tobe operable independently of each other and being selectively actuatablealone through software of coupleable to each other in a dual operativecombination; said video scanner and said laser scanner being arranged ona common beam path for detecting the same measuring point on aworkpiece. .Iaddend. .Iadd.26. An installation as claimed in claim 25,wherein a single said software is provided for the actuation of theentire multi-sensor scanning system. .Iaddend. .Iadd.27. An installationas claimed in claim 25, comprising a spindle movable in a Z-coordinatedirection, said spindle mounting said video scanner and said laserscanner. .Iaddend. .Iadd.28. An installation as claimed in claim 27,wherein said laser scanner is employable in a scanning operation andalso in autofocus. .Iaddend. .Iadd.29. An installation as claimed inclaim 28, further comprising a measuring carriage, said spindle beingmounted on said measuring carriage, wherein said laser scanner duringscanning operation non-contactingly follows the surface contour of aworkpiece being measured at a constant distance therefrom along the Xand Y-coordinate directions, said laser scanning system comprising firstand second interlinked closed control circuits, said first controlcircuit determining the transmitting power of the laser relative to thereflective characteristics of the workpiece and in dependence upon areceiving signal in a receiver controlling a transmission signal in atransmitter, and said second control circuit controlling the continualfollow-up of the measuring carriage and spindle in the Z-direction intoan optimum focusing plane. .Iaddend. .Iadd.30. An installation asclaimed in claim 29, wherein said receiver includes differentiatingdiodes for generating a differential signal in conformance with thefocusing setting of a lens, said Z-axis being automatically positionedthrough a liner amplifier and servomotor into the focusing plane..Iaddend. .Iadd.31. An installation as claimed in claim 30, wherein saidmeasuring carriage and spindle for the Z-axis includes a measuringsystem with a glass measuring rod, and the present position of elevationis conveyed to a main computer. .Iaddend. .Iadd.32. An installation asclaimed in claim 29, wherein the fundamental machine unit comprises aportal-like gantry structure having a solid base, selectively includinga measuring turntable for receiving the workpiece, and a cross-carriersupporting the measuring carriage for the spindles for longitudinaldisplacement thereon in a direction of travel at right angles or equallydirected relative to said gantry structure, said measuring carriage orcarriages, said spindle being controllable from a control panel and theobtained results of measurement being recordable on a picture screen ofa display unit or selectively on a printer. .Iaddend.